This project explores the fundamental chemical properties of porphyrins and fullerenes with the goal of discovering new chemistry that underpins the molecular level understanding of biology and medicine. It focuses on the spin states of iron, weak interactions between metals and ligands, supramolecular chemistry and new reactivity of C60. The specific aims include a search for the 'missing' pure S = 3/2 spin state of iron(III) porphyrins and an investigation into the reversal of ligand field strength order of OH- and H2O in the new "Magnetochemical Series" versus the familiar Spectrochemical Series. A superstructured metalloporphyrin, that gave rise to the first insoluble complex of an alkane, will be used to investigate potential complexes of xenon. Fullerene cation chemistry will be explored to develop fullerenium ions as synthons for clean monofunctionalization of C60. The weak, labile dimerization hypothesis for fulleride ions, e.g. the formation of [(C60)2]- and [(C60)2]2-, will be tested by the construction of supramolecular traps for monomeric and dimeric fullerene moieties. Self assembling metalloporphyrin cubes and boxes have been designed to encapsulate C60, C70 and (C60)2 and their respective fulleride anions. Cationic C60 complexes of ruthenium and osmium are being prepared for biological testing as anti-viral and anti-cancer drugs. The structural characterization of functional models for the heme a3/CuB active site of cytochrome oxidase will be pursued. Emphasis in all of these studies will be placed on the definitive characterization of analytically pure materials by X-ray crystallography, electrochemical methods and a variety of spectroscopic methods (NMR, IR, electronic spectroscopy including NIR, Mossbauer, resonance Raman, etc). An understanding of this fundamental bioinorganic chemistry must underlie medical approaches to the therapy of metalloprotein disorders (thalassemias, sickle cell anemia, etc). Fullerenes have potential applications as radiopharmaceuticals, anti-virals, anti-cancer drugs, photodynamic therapy agents and as MRI agents.